The Braille code is widely used by blind people to read and write. Devised by the blind Frenchman Luis Braille, the Braille code is written in Braille cells, wherein each Braille cell is made up of six or eight dot positions which are arranged in a rectangle comprising two columns of three or four dots each. Each Braille cell represents a character, a sign or a number according to the commonly known Braille code. Today, different Braille codes or code pages are used to map character sets of different language to the Braille cells. Further, there are different Braille codes which are used for different purposes like mathematics or music.
Braille may be produced using a slate and stylus wherein each dot is created from the back of a page, writing in mirror image by hand. Further, there are Braille type writers such as the Perkins Brailler which produce Braille embossings on a sheet of paper. Modern Braille embossers may be connected to a computer and allow “printing” of Braille characters with computer based word processors.
A beneficial tool for blind people using a computer is a refreshable Braille display. Such a Braille display or Braille terminal is an electromechanical device for displaying Braille characters. Usually, dots are raised through holes in a flat touch-and-sense surface and blind people may recognize the displayed Braille characters by touching and sensing the Braille line which typically comprises 40 or 80 Braille cells.
The refreshable Braille display may be used to read text tactually that is displayed visually on a computer monitor. The refreshable Braille display may be connected to a personal computer via a serial or USB cable and produces a Braille output by help of a plurality of small plastic or metal pins that move up and down to display the Braille characters in the Braille cells of the touch-and-sense surface in the Braille line. However, Braille display systems are limited in that, Braille characters of the common Braille code may be displayed only. In modern communication applications which are available to non-blind people, for example in chat or talk applications, there are further options for communication. For example, there are symbols or pictures which are not a part of the Braille coding system but which are frequently used for communication and which allow summarizing a complex feedback or a mood of the author by help of well known icons or graphical representations. Due to the limited operability of today's Braille systems, this way of communicating is refused to blind people who operate their personal computer using a refreshable Braille display.